Patella exerciser



FIG. 1 is a side elevational view of a patella exerciser showing my newdesign;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a cross-sectional view thereof taken along line 4--4 of FIG.1.

The ornamental design for a patella exerciser, as shown and described.